Method for manufacturing a thin film magnetic head

ABSTRACT

A first magnetic film is formed in a primary pattern which is larger than its definitive pattern and of which edges are located within frames to be used in a frame-plating method for the second magnetic film after forming the first pole portion and the gap film. Then, the second magnetic film is formed by the frame-plating method, and the first magnetic film is etched into the definitive pattern through the second magnetic film as a mask.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a method for manufacturing a thin filmmagnetic head usable for a magnetic recording and reproducing drivedevice such as a magnetic disk drive device.

[0003] 2. Related Art Statement

[0004] For realizing a high recording density in a magnetic disk using athin film magnetic head, it is required that data amount (data density)to be restored in the unit area of the magnetic disk is enhanced. Thesurface recording density depends on performance of a recording element,and can be enhanced by shortening the gap length between the recordingpoles of the recording element.

[0005] The surface recording density can be also enhanced by increasingthe track number to be recorded in the magnetic disk. The track numberrecordable in the magnetic disk is normally represented as “TPI (trackper inch)”. The TPI performance of the recording element can be enhancedby downsizing the recording head to determine the width of the datatrack. The size of the recording head is normally known as a trackwidth.

[0006] However, the shortening of the gap length between the recordingpoles and the narrowing of the track width decrease the magnetic flux inbetween the recording poles, resulting in the degradation of theoverwrite performance. Therefore, in view of recording performance, theshortening of the gap length and the narrowing of the track width cannot employed for a high density recording magnetic disk having a highcoercivity Hc.

[0007] To solve this problem, the recording pole structure in which in arecording pole portion, a magnetic film having a high saturated magneticflux density (a first magnetic film) is provided adjacent to a gap filmand a second magnetic film having a smaller saturated magnetic fluxdensity than the first magnetic film is provided on the first magneticfilm is suggested and practically used. For example, the specificationof U.S. Pat. No. 5,606,478 discloses that the part of the recording poleportion adjacent to the gap film is made of a magnetic material having ahigher saturated magnetic flux, for example Ni₅₅Fe₄₅, than the magneticmaterial having a NiFe composition which is usually used for the poleportion of the above thin film magnetic head. However, the Ni₅₅Fe₄₅material has only 1.4 T to 1.5 T, so that the recording performance isrestricted..

[0008] In addition, the specification of Kokai Publication Kokai Hei5-73839 (JP A 5-73839) discloses that an underfilm to plate a bottommagnetic core and a top magnetic core is made of a magnetic materialhaving a higher saturated magnetic flux density than the magneticmaterials constituting the bottom magnetic core and the top magneticcore.

[0009] In defining the track width of the recording pole portion usingthe above means in those related documents, the underfilm made of themagnetic film having the higher saturated magnetic flux density has tobe etched by milling, etc. In the etching process, the part of themagnetic material constituting the underfilm is re-stuck on the sidesurfaces, etc. of the pole portion, resulting in the increase of thetrack width. This means the opposite result to the narrowing of thetrack width. Moreover, the re-stuck portion of the pole portion usuallyhas inferior magnetic characteristics, so that the electromagneticconversion characteristics of the pole portion is deteriorated.

[0010] If the underfilm is thinner, the re-sticking can be reduced.However, the thinner underfilm can not realize the essential object ofenhancing the recording performance by making the underfilm of themagnetic material having a high saturated magnetic flux density. Theabove related documents do not disclose the means for solving the aboveproblems due to the re-sticking.

SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide a method formanufacturing a thin film magnetic head in which the re-sticking isalmost never brought about if a magnetic film, provided adjacent to awrite gap film, having a high saturated magnetic flux density isthicker.

[0012] It is another object of the present invention to provide a methodfor manufacturing a thin film magnetic head having a recording polestructure of high recording performance.

[0013] For accomplishing the objects, this invention is directed to amethod for manufacturing a thin film magnetic head including a-recordingpole portion. The recording pole portion includes a first pole portion,a gap film adjacent to the first pole portion and a second pole portionadjacent to the gap film. The second pole portion has a first magneticfilm and a second magnetic film. The first magnetic film has a highersaturated magnetic flux density than the second magnetic film and isprovided adjacent to the gap film, and the second magnetic film isprovided adjacent to the first magnetic film.

[0014] In manufacturing the above thin film magnetic head, themanufacturing method of the present invention has the steps of forming,on the gap film, the first magnetic film in a primary pattern afterforming the first pole portion and the gap film and of forming thesecond magnetic film by a frame-plating method.

[0015] In the above steps, the primary pattern is formed so that itssize can be larger than the definitive pattern of the first magneticfilm and its edges can be located within frames to be used in theframe-plating method.

[0016] According to the manufacturing method, the etching of the firstmagnetic film in the definitive pattern by dry-etching such as RIE ormilling using the second magnetic film as a mask can remove the re-stuckmagnetic material of the first magnetic film from the both side surfacesof the first and second magnetic films in the track direction. After thefirst magnetic film is etched in the definitive pattern, the re-stickingdoes not occur. Consequently, even if the first magnetic film having ahigh saturated magnetic flux density is thicker, the re-sticking almostnever occur.

[0017] Moreover, this invention discloses two modes of the manufacturingmethod concretely.

First Mode-Manufacturing Method

[0018] The first mode-manufacturing method includes the following steps.

[0019] First of all, a magnetic film to be the first magnetic film isformed on the gap film. Then, a mask having a pattern larger than thedefinitive pattern of the first magnetic film is formed on the magneticfilm. The part of the magnetic film uncovered with the mask is removedto form the first magnetic film having the primary pattern.

[0020] Subsequently, an plate underfilm is formed on the first magneticfilm having the primary pattern and the gap film. Then, frames forframe-plating the second magnetic film is formed on the plate underfilm.The frames are separated on the first magnetic film in the paralleltrack direction thereto and cover the both edges of the first magneticfilm and the gap film around the both edges in the track direction.

[0021] Subsequently, a plate film to be the second magnetic film isstuck on the part of the plate underfilm uncovered with the frame, andthereafter, the frame is removed.

[0022] Next, the part of the plate underfilm which is exposed followedby the removing of the frame is removed. Since the plate underfilm isextremely thin, the material constituting the plate underfilm is notstuck on the both side surfaces of the first and second magnetic filmsin the track direction even if the plate underfilm is removed bydry-etching such as milling or reactive ion etching (hereinafter,abbreviated to “RIE”). Moreover, since the first magnetic film ispatterned to have the primary pattern, in removing the plate underfilm,only the plate underfilm has to be etched and the first magnetic filmdose not have to. Therefore, the above conventional problems due to there-sticking of magnetic material constituting the first magnetic filmcan be prevented.

[0023] Furthermore, although the second magnetic film is exposed to thedry-etching in the above removing process of the plate underfilm by thedry-etching, the extremely thin plate underfilm can repress thereduction of the second magnetic film to the utmost. Therefore, the thinfilm magnetic head having the recording pole structure with a highrecording performance can be provided.

[0024] Then, the plate underfilm is removed and a mask to cover thefirst and second magnetic films is formed. The parts of the plate filmand the plate underfilm uncovered with the mask are removed. The platefilm and the plate underfilm may be removed by RIE, milling, chemicaletching or the like. Since the first and second magnetic films arecovered with the mask, they are not reduced.

[0025] The mask is removed and the first magnetic film is patterned inthe definitive pattern. Since the first magnetic film has the primarypattern which is larger than the definitive pattern and of which edgesare located within the frame to be used in the frame-plating method, theetching of the first magnetic film can remove the re-stuck magneticmaterial of the first magnetic film from the both side surfaces of thefirst and second magnetic films in the track direction in patterning thefirst magnetic film in the definitive pattern by dry-etching such as RIEor milling.

[0026] Moreover, at the time of patterning the first magnetic film, theplate film to be the second magnetic film and the plate underfilm arealready removed around the first magnetic film. Therefore, if themagnetic material of the first magnetic film is re-stuck in the bothside surfaces of the first and second magnetic films in the trackdirection due to the patterning of the first magnetic film bydry-etching such as RIE or milling, the re-stuck magnetic material canbe removed from the both sides of the first and second magnetic filmshaving no obstacles in the track direction. Therefore, if the firstmagnetic film having a high saturated magnetic flux density providedadjacent to the gap film is thick, the re-sticking almost never occur.

[0027] Furthermore, since the reduction of the second magnetic film canbe repressed to the utmost through the whole process, the thin filmmagnetic head having the recording pole structure having a highrecording performance can be provided.

Second Mode-Manufacturing Method

[0028] The second mode-manufacturing method includes the followingsteps.

[0029] First of all, a non-magnetic film is formed entirely on a gapfilm. Then, a hollowed hole having a pattern corresponding to theprimary pattern of the first magnetic film is formed in the non-magneticfilm.

[0030] Subsequently, a magnetic film to be the first magnetic film isformed on the non-magnetic film and the part of the gap film exposed tothe bottom of the hollowed hole.

[0031] Next, the first magnetic film is flattened so that the surface ofthe part of the first magnetic film in the hollowed hole can have thesubstantially same level as that of the non-magnetic film to form theprimarily patterned first magnetic film.

[0032] Thereafter, the similar steps to the first mode-manufacturingmethod are carried out. As a result, the similar operation and effect tothe first mode-manufacturing method can be obtained and the objects ofthe present invention can be achieved.

[0033] The other objects, constructions and advantages of the presentinvention will be described in detail, with reference to the attacheddrawings in the following embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] For a better understanding of this invention, reference is madeto the attached drawings, wherein:

[0035]FIG. 1 is a perspective view of a thin film magnetic head obtainedby the manufacturing method of the present invention,

[0036]FIG. 2 is a cross sectional view of the thin film magnetic headshown in FIG. 1,

[0037]FIG. 3 is a cross sectional view of a thin film magnetic headdifferent from that of FIG. 1

[0038]FIG. 4 is a cross sectional view showing one step included in thefirst mode-manufacturing method of the thin film magnetic head shown inFIGS. 1 and 2,

[0039]FIG. 5 is a cross sectional view showing the step after the stepof FIG. 4,

[0040]FIG. 6 is a cross sectional view showing the step after the stepof FIG. 5,

[0041]FIG. 7 is a cross sectional view showing the step after the stepof FIG. 6,

[0042]FIG. 8 is a cross sectional view showing the step after the stepof FIG. 7,

[0043]FIG. 9 is a cross sectional view showing the step after the stepof FIG. 8,

[0044]FIG. 10 is a plan view of the step shown in FIG. 9,

[0045]FIG. 11 is a cross sectional view showing the step after the stepof FIGS. 9 and 10,

[0046]FIG. 12 is a cross sectional view showing the step after the stepof FIG. 11,

[0047]FIG. 13 is a cross sectional view showing the step after the stepof FIG. 12,

[0048]FIG. 14 is a cross sectional view showing the step after the stepof FIG. 13,

[0049]FIG. 15 is a cross sectional view showing the step after the stepof FIG. 14,

[0050]FIG. 16 is a cross sectional view showing the step after the stepof FIG. 15,

[0051]FIG. 17 is a cross sectional view showing the step after the stepof FIG. 16,

[0052]FIG. 18 is a cross sectional view showing one step included in thesecond mode-manufacturing method of the thin film magnetic head shown inFIGS. 1 and 3,

[0053]FIG. 19 is a cross sectional view showing the step after the stepof FIG. 18,

[0054]FIG. 20 is a cross sectional view showing the step after the stepof FIG. 19,

[0055]FIG. 21 is a cross sectional view showing the step after the stepof FIG. 20,

[0056]FIG. 22 is a cross sectional view showing the step after the stepof FIG. 21,

[0057]FIG. 23 is a cross sectional view showing the step after the stepof FIG. 22,

[0058]FIG. 24 is a cross sectional view showing the step after the stepof FIG. 23,

[0059]FIG. 25 is a cross sectional view showing the step after the stepof FIG. 24,

[0060]FIG. 26 is a cross sectional view showing the step after the stepof FIG. 25,

[0061]FIG. 27 is a cross sectional view showing the step after the stepof FIG. 26,

[0062]FIG. 28 is a cross sectional view showing the step after the stepof FIG. 27,

[0063]FIG. 29 is a cross sectional view showing the step after the stepof FIG. 28,

[0064]FIG. 30 is a cross sectional view showing the step after the stepof FIG. 29,

[0065]FIG. 31 is a cross sectional view showing one step included in aconventional manufacturing method of a thin film magnetic head,

[0066]FIG. 32 is a cross sectional view showing the step after the stepof FIG. 31,

[0067]FIG. 33 is a cross sectional view showing the step after the stepof FIG. 32, and

[0068]FIG. 34 is a cross sectional view showing the step after the stepof FIG. 33.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Thin Film Magnetic Head ina First Embodiment

[0069]FIG. 1 is a perspective view showing a thin film magnetic headobtained by the manufacturing method of the present invention, and FIG.2 is a cross sectional view of the thin film magnetic head depicted inFIG. 1. In the figures, the size of each part is exaggerated. Theillustrated thin film magnetic head comprises a slider 1, at least onerecording element 2 and a reading element 3 composed of amagnetoresistive effective element (hereinafter, often called as a “MRreading element”).

[0070] The slider 1 has rail parts 11 and 12 on its opposing surface toa magnetic recording medium, and the surfaces of the rail parts 11 and12 are employed as air bearing surfaces (hereinafter, often called as“ABSs”) 13 and 14. The slider 1 does not always have the two rail parts11 and 12, and may have one to three rail parts. Moreover, the slidermay have a flat surface having no rail part. For improving its floatingcharacteristic, the slider may have an opposing surface with variousgeometrical shape to a recording medium. The method of the presentinvention can be applied for the sliders having the above various typesof surface. The slider 1 is made of a ceramic material such as AlTiC.

[0071] The recording elements 2 and MR reading element 3 are provided oneither edge or both edges of the rail parts 11 and 12 in a recordingmedium-moving direction a1. The recording medium-moving direction a1corresponds to the flow out direction of air at the time of the highvelocity moving of the recording medium.

[0072] The recording element 2 is stacked on the MR reading element 3.Conversely, the MR reading element 3 may be stacked on the recordingelement 2. The recording element 2 includes a recording pole portion.The recording pole portion has a first pole portion 21, a gap film 24adjacent to the first pole portion 21 and a second pole portion 22adjacent to the gap film 24.

[0073] The first pole portion 21 includes a magnetic film 221. Themagnetic film 211 is formed, of a soft magnetic material such as NiFe,CoFe, CoNiFe, in a thickness of 0.5 μm to 4 μm. The magnetic film 211 iselongated backward from the ABSs 13 and 14 to function as a first yokeportion.

[0074] The gap film 24 may be made of a non-magnetic insulating materialsuch as Al₂O₃, SiO₂ or a non-magnetic metallic material. In making thefilm of the non-magnetic insulating material such as Al₂O₃, SiO₂, asputtering method etc. may be used. In making the film of thenon-magnetic metallic material, a plating method or a sputtering methodcan be used. The thickness of the gap film is preferably 0.01-0.5 μm.

[0075] The second pole portion 22 includes a first magnetic film 221 anda second magnetic film 222. The first magnetic film 221 has a largersaturated magnetic flux density than the second magnetic film 222 and islocated adjacent to the gap film 24. The first magnetic film 221 is madeof a large coercivity magnetic material such as FeN, FeMN, FeMC, FeMON(M=B, Al, Si, Cr, Ti, Hf, Nb, Ta, Zr, Mo, etc.). The second magneticfilm 222 is formed, of a soft magnetic material such as NiFe, CoFe,CoFeNi, in a thickness of about 3 μm to 5 μm. As the forming method, adry-etching method to narrow the track width as well as a frame-platingmethod may be employed. The details will be described hereinafter.

[0076] The second magnetic film 222 is adjacent to the first magneticfilm 221. The second magnetic film 222 is elongated backward from theABSs 13 and 14 alongside the surface of the coil insulating film 25 tosupport a coil film 23 to function as a second yoke portion. Thebackward portion of the second magnetic film 222 is joined to themagnetic film 211 elongated from the first pole portion 21 at a joiningportion 223 so as to complete a magnetic circuit. In FIG. 2, the firstmagnetic film 221 is provided only at the recording pole portion, butmay be entirely under the second magnetic film 222.

[0077] The coil film 23 is formed on the coil insulating film 25 so asto wind spirally the joining portion 223. The coil insulating film 25 ispreferably formed by hardening a photoresist material. The layer numberand thickness of the coil insulating film 25 depends on the layer numberof the coil film 23 and the coil supporting structure. Generally, thecoil insulating film has a thickness of about 3 μm to 20 μm. The coilfilm 23 is formed of a conductive material such as Cu. The thickness ofthe coil film 23 is preferably 2-5 μm. The coil film 23 may be formed bya frame plating method, etc. The coil film 23 constitutes a thin filmmagnetic circuit with the magnetic film 211 elongated from the firstpole portion 21, the first and second magnetic films 221, 222 and thegap film 24. The coil film 23 is supported by the coil supporting film25 and is formed so as to wind spirally the joining portion of the yokeportion. Both ends of the coil film 23 are conductively connected totaking out electrodes 27 and 28 (see, FIG. 1). In this embodiment, thecoil film 23 has a two-layered structure.

[0078] The area around the first and second pole portions 21, 22 and thegap film 24 is embedded by a non-magnetic insulating film 27 made ofAl₂O₃, SiO₂, etc.

[0079] The recording element 2 is covered with a protection film 26entirely. The protection film 26 may be formed of an insulating materialsuch as Al₂O₃, SiO₂, etc. Moreover, the thickness of the protection film26 is preferably about 5 μm to 50 μm by sputtering, etc.

[0080] As the MR reading element, various film structures have beenproposed and practically used. For example, a MR element using ananisotropic magnetoresistive (IMR) effective element made of permally,etc., a giant magnetoresistive (GMR) effective film made of a spin valvestructure-magnetic material or a perovskite type magnetic material or aferromagnetic tunnel connection element is exemplified. In thisinvention, any kind of the above film structures may be employed. The MRreading element 3 is placed, between a first shield film 31 and thefirst magnetic film 211 doubling as a second shield film, in aninsulating film 32. The insulating film 32 is made of alumina, etc. TheMR reading element 3 is connected to the taking out-electrodes 33 and 34(see, FIG. 1) via a leading conductor 35 (see, FIG. 2).

[0081] In the illustrated thin film magnetic head, since the slider 1has ABSs 13 and 14 on its medium opposing surface, and the recordingelement 2 and the MR reading element 3 are provided on the slider 1, thethin film magnetic head can be employed as a floating type thin filmmagnetic head by combining a magnetic recording medium such as amagnetic disk.

[0082] Since the backward portion of the second magnetic film 222 ismagnetically joined to the magnetic film 211 elongated from the firstpole portion 21, the magnetic field generated by flowing a writingcurrent in the coil film 23 can be effectively conducted to the firstpole portion 21 and the second pole portion 22 via the second magneticfilm 222 and the magnetic film 221 elongated from the first pole portion21.

[0083]FIG. 3 is a cross sectional view showing another thin filmmagnetic head obtained by the manufacturing method of the presentinvention. In this figure, the same references are given to the similarparts to the ones in FIG. 2. The thin film magnetic head illustrated inFIG. 3 is characterized in that the first pole portion 21 has, on themagnetic film 211, a magnetic film 212 with a larger saturated magneticflux density than the magnetic film 211. The magnetic film 212 is madeof a large saturated magnetic flux density material such as FeN, FeMN,FeMC, FeMON (M=B, Al, Si, Cr, Ti, Hf, Nb, Ta, Zr, Mo, etc.).

[0084] Next, the example in which the thin film magnetic head in FIGS. 1and 2 is made by the first mode-manufacturing method will be describedhereinafter. FIGS. 4-17 are cross sectional views showing the stepsincluded in the first mode-manufacturing method of the presentinvention. In these figures, the same references are given to thesimilar parts to the ones in FIGS. 1 and 2. The manufacturing method isperformed on a wafer.

[0085] First of all, as shown in FIG. 4, after the first shielding film31, the insulating film 32, the MR reading element 3, the magnetic film211 to be a second shielding film and the gap film 24 are formed by awell known process, a magnetic film M1 to constitute the first magneticfilm 221 (see, FIG. 2) is formed on the gap film 24. The magnetic filmM1 is made of a large coercivity magnetic material such as FeN, FeMN,FeMC, FeMON (M=B, Al, Si, Cr, Ti, Hf, Nb, Ta, Zr, Mo, etc.). Themagnetic film MI may be formed by sputtering, plating or the like.

[0086] Next, as shown in FIG. 5, a mask S1 having a pattern larger thanthe definitive pattern of the first magnetic film 221 is formed on themagnetic film M1 to constitute the first magnetic film 221. The mask S1may be made of a photoresist material by a photolithography process.

[0087] Subsequently, as shown in FIG. 6, the part of the magnetic filmM1 uncovered with the mask S1 is removed. A dry-etching method such asmilling or RIE is suitable for the removing means. Thereafter, the maskS1 is removed and the first magnetic film 221 having the primary patternis obtained as shown in FIG. 7. The primary pattern of the firstmagnetic film 221, as described later, is larger than the definitivepattern thereof, and edges of the primary pattern are located within theframes to be used in the frame-plating method for the second magneticfilm.

[0088] Next, as shown in FIG. 8, a plate underfilm M2 is formed on thefirst magnetic film having a primary pattern and the gap film 24. Theplate underfilm M2 is formed, of a magnetic material such as NiFe, in anextremely thin thickness of 5 μm to 100 μm by sputtering, for example.

[0089] Subsequently, as shown in FIG. 9 and 10, frames F1 are formed onthe plate underfilm M2. The frames F1 are separated, on the firstmagnetic film 221, by distance PW2 in the track direction TR1 parallelto the surface of the film 221 and cover both edges of the film 221 andthe part of the gap film 24 around the edges in the track direction TR1.The edges of the first magnetic film 221 are located within the framesF1. The Frames F1 may be made of a photoresist material by aphotolithography process.

[0090] Next, as shown in FIG. 11, a plate film M3 to constitute thesecond magnetic film 222 (see, FIG. 2) is stuck on the part of the plateunderfilm M2 uncovered with the frames F1. The plate film M3 is formed,of a soft magnetic material such as NiFe, CoFe, CoFeNi, in a thicknessof 3 μm to 5 μm.

[0091] The frames F1 are removed as shown in FIG. 12, and the part ofthe plate underfilm M2 exposed after the removing of the frames isremoved. The plate underfilm M2 may be removed by dry-etching such asmilling or RIE. Since the plate underfilm M2 is extremely thin, asmentioned above, the material constituting the plate underfilm is notre-stuck on the both side surfaces of the first and second magneticfilms 221 and 222 in the track direction TR1 when the plate underfilm M2is removed by dry-etching such as milling or RIE. Moreover, since thefirst magnetic film 221 is formed in the primary pattern, in theremoving process of the plate underfilm M2, only the plate underfilm M2has to be etched and the first magnetic film 221 does not have to beetched. Therefore, the conventional problems due to the re-sticking ofthe first magnetic film 221 can be prevented.

[0092] Moreover, although in the above removing process of the plateunderfilm M2 using dry-etching, the second magnetic film 222 is exposedto the process, the reduction of the second magnetic film 222 can berepressed to the utmost because the plate underfilm M2 is extremelythin. Therefore, the thin film magnetic head having the recording polestructure with high recording performance.

[0093] Next, as shown in FIG. 14, after the plate underfilm M2 isremoved, a mask S2 to cover the first and second magnetic films 221, 222is formed. The mask S2 is made of a photoresist material by aphotolithography process.

[0094] Subsequently, as shown in FIG. 15, the parts of the plate film M3and the plate underfilm M2 uncovered with the mask S2 are removed. Theplate film M3 and the plate underfilm M2 may be removed by RIE, milling,chemical etching or the like. Since the first and second magnetic film221, 222 are covered with the mask S2, they are not reduced in thisstep.

[0095] Next, as shown in FIG. 16, the mask S2 (see, FIGS. 14 and 15) isremoved, and the first magnetic film 221 is patterned in its definitivepattern. The patterning is carried out by dry-etching E3 such as millingor RIE. In this way, as shown in FIG. 17, the writing pole portion isformed in the definitive pattern to have a given track width PW2.

[0096] In the above process, since the first magnetic film 221 has theprimary pattern which is larger than the definitive pattern thereof andof which edges are located within the frames F1 to be used in theframe-plating method, the etching of the first magnetic film 221 by thedry-etching such as RIE or milling can remove the re-stuck material ofthe first magnetic film 221 from both side surfaces of the first andsecond magnetic films 221, 222 in the track direction TR1.

[0097] Moreover, in the etching of the first magnetic film 221 into thedefinitive pattern, the parts of the plate film and the plate underfilm,which are stuck for forming the second magnetic film 222, are removedfrom the area around the first magnetic film 221. Therefore, if thematerial constituting the first magnetic film 221 is stuck on both sidesurfaces of the first and second magnetic films 221, 222 in the trackdirection TR1 due to the pattering of the film 221 by the dry-etchingsuch as RIE or milling, the material can be removed by etching from bothsides of the magnetic films having no obstacles in the track directionTR1.

[0098] Therefore, if the first magnetic film having a high saturatedmagnetic flux density is formed thicker adjacent to the gap film 24, there-sticking almost never occur.

[0099] Furthermore, the reduction of the second magnetic film 222 can berepressed to the utmost through the whole steps. Consequently, the thinfilm magnetic head having the recording pole structure with highrecording performance can be obtained.

Second Mode-Manufacturing Method

[0100] FIGS. 18-30 are cross sectional views showing the steps includedin the second mode-manufacturing method of the present invention.

[0101] First of all, as shown in FIG. 18, the non-magnetic film 27 isformed over the gap film 24. The non-magnetic material may be formed ofan inorganic insulating material such as Al₂O₃, SiO₂ or a non-magneticmetallic material by sputtering. The non-magnetic film 27 may be formedflat as shown in FIG. 2. The thickness of the non-magnetic film 27 isdetermined by the thickness of the first magnetic film 221 to beobtained conclusively.

[0102] Next, as shown in FIG. 19, a hollowed hole Hi having the patterncorresponding to the primary pattern of the first magnetic film 221(see, FIG. 2) is formed in the non-magnetic film 27. The hollowed holeH1 can be formed by dry-etching such as RIE or milling for thenon-magnetic film 27 via a mask.

[0103] Subsequently, as shown in FIG. 20, a magnetic film M4 toconstitute the first magnetic film 221 (see, FIG. 2) is formed on theremaining non-magnetic film 27 and the part of gap film 24 exposed tothe hollowed hole H1. The thickness and material of the magnetic film M4may be employed as in the first mode-manufacturing method.

[0104] Next, as shown in FIG. 21, the magnetic film M4 is flattened sothat its part formed in the hollowed hole H1 can have the substantiallysame level as that of the remaining non-magnetic film 27 to form thefirst magnetic film 221 having the primary pattern. The primary patternof the first magnetic film 221, as described later, is larger than thedefinitive pattern thereof, and edges of the primary pattern are locatedwithin the frames to be used in the frame-plating method for the secondmagnetic film. The flattening of the magnetic film M4 may be carried outby chemical mechanical polishing (CMP).

[0105] Thereafter, the similar steps to the ones in the firstmode-manufacturing method are performed. That is, as depicted in FIG.22, a plate underfilm M5 is formed on the first magnetic film 221 andthe remaining non-magnetic film 27. The plate underfilm M5 correspondsto the plate underfilm M2 (see, FIG. 8)in the first mode-manufacturingmethod.

[0106] Subsequently, as shown in FIG. 23, frames F2 are formed in theplate underfilm M5. The frames F2 are separated, on the first magneticfilm 221, by distance PW2 in the track direction TR1 parallel to thesurface of the film 221 and cover both edges of the film 221 and thepart of the gap film 24 around the edges in the track direction TR1. Theedges of the first magnetic film 221 are located within the frames F1.

[0107] Next, as shown in FIG. 24, a plate film M6 to constitute thesecond magnetic film 222 is stuck on the parts of the plate underfilm M5uncovered with the frames F2.

[0108] Subsequently, as shown in FIG. 25, the frames F2 are removed.Then, as shown in FIG. 26, the parts of the plate underfilm M5 exposedafter the removing of the frames F2 are removed. Since generally, theplate underfilm M5 is extremely thin, the material constituting theplate underfilm M5 is not stuck on both side surfaces of the first andsecond magnetic films 221, 222 in the track direction TR1 when the plateunderfilm is removed by dry-etching such as RIE or milling. Moreover,since the first magnetic film 221 is already patterned flat so as tohave the primary pattern in the above flattening process (see, FIG. 21),in the above removing process of the plate underfilm M5, only the plateunderfilm M5 is etched and the first magnetic film 221 is not etched.Therefore, the conventional problems due to the re-sticking of the firstmagnetic film 221 having a high saturated magnetic flux density can beprevented.

[0109] Moreover, although in the above removing process of the plateunderfilm M5 using dry-etching, the second magnetic film 222 is exposedto the process, the reduction of the second magnetic film 222 can berepressed to the utmost because the plate underfilm M5 is extremelythin. Therefore, the thin film magnetic head having the recording polestructure with high recording performance can be provided.

[0110] Next, as shown in FIG. 27, after the plate underfilm M5 isremoved, a mask S3 to cover the first and second magnetic films 221, 222is formed.

[0111] Subsequently, as shown in FIG. 28, the parts of the plate film M6and the plate underfilm M5 uncovered with the mask S3 are removed. Theplate film M6 and the plate underfilm M5 may be removed by RIE, milling,chemical etching or the like. Since the first and second magnetic film221, 222 are covered with the mask S3, they are not reduced in thisstep.

[0112] Next, as shown in FIG. 29, the mask S3 (see, FIG. 28) is removed,and dry-etching E5 such as RIE or milling is performed. As a result, asshown in FIG. 30, the first magnetic film 221 is patterned in itsdefinitive pattern having track width PW2. In the above process, sincethe first magnetic film 221 has the primary pattern which is larger thanthe definitive pattern thereof and of which edges are located within theframes F1 to be used in the frame-plating method, the etching of thefirst magnetic film 221 by the dry-etching such as RIE or milling canremove the re-stuck material of the first magnetic film 221 from bothside surfaces of the first and second magnetic films 221, 222 in thetrack direction TR1.

[0113] Moreover, in the etching of the first magnetic film 221 into thedefinitive pattern, the parts of the plate film M6 and the plateunderfilm M5 (see, FIG. 27), which are stuck for forming the secondmagnetic film 222, are removed from the area around the first magneticfilm 221. Therefore, if the material constituting the first magneticfilm 221 is stuck on both side surfaces of the first and second magneticfilms 221, 222 in the track direction TR1 due to the pattering of thefilm 221 by the dry-etching such as RIE or milling, the material can beremoved by etching from both sides of the magnetic films having noobstacles in the track direction TR1.

[0114] Therefore, if the first magnetic film having a high saturatedmagnetic flux density is formed thicker adjacent to the gap film 24, there-sticking almost never occur. Furthermore, since the reduction of thesecond magnetic film 222 can be repressed to the utmost through thewhole steps, the thin film magnetic head having the recording polestructure with high recording performance can be obtained.

[0115] Compared with the conventional manufacturing steps shown in FIGS.31-34, the advantages in the manufacturing method of the presentinvention can be much clarified. In the conventional manufacturingmethod, first of all, as shown in FIG. 31, a magnetic film M7 toconstitute the first magnetic film 221 (see, FIG. 2) is formed, framesF4 are formed on the first magnetic film M7. Next, as shown in FIG. 32,a plate film M8 is stuck on the part of the magnetic film M7 uncoveredwith the frame F4.

[0116] Subsequently, as shown in FIG. 33, the frames F4 (see, FIG. 32)are removed, and as shown in FIG. 34, dry-etching E6 such as RIE ormilling for the magnetic film M7 is performed using the second magneticfilm 222 composed of the plate film M8 to define the track width of therecording track.

[0117] As mentioned above, conventionally, in defining the track widthof the recording pole portion, the magnetic film M7 having a highsaturated magnetic flux density as an underfilm has to be etched bymilling or the like using the second magnetic film 222 as a mask. In themilling process, the magnetic materials constituting the magnetic filmsM7 and M8 are stuck on the side surfaces, etc. of the pole portion. There-stuck portions A1 (see, FIG. 34) enlarge the track width into widthPW3 from desired width PW2. This means the opposite result to thenarrowing of the track width. Moreover, the re-stuck portions A1 usuallyhas inferior magnetic characteristics, so that the electromagneticconversion characteristics of the pole portion is deteriorated.

[0118] If the magnetic film M7 is formed thinner, the re-sticking can berepressed. However, the thinner magnetic film M7 degrades the recordingperformance of the pole portion, and can not achieve the original objectto enhance the recording performance. It is apparent that themanufacturing method of the present invention can solve the aboveproblems.

[0119] Although in the above embodiments, the manufacturing method ofthe present invention is applied for the thin film magnetic head shownin FIG. 2, it is obvious that the manufacturing method can be appliedfor the thin film magnetic head in FIG. 3 by varying more or less thesteps included in the above manufacturing method.

[0120] This invention has been described in detail with reference to theabove preferred concrete embodiments, but it is obvious for the ordinaryperson skilled in the art that various modifications can be made in itsconfiguration and detail without departing from the scope of thisinvention.

[0121] As mentioned above, this invention can provide the followingeffects:

[0122] (a) A method for manufacturing a thin film magnetic head in whichthe re-sticking is almost never brought about if a magnetic film,provided adjacent to a gap film, having a high saturated magnetic fluxdensity is thicker can be provided.

[0123] (b) A method for manufacturing a thin film magnetic head having arecording pole structure of high recording performance can be provided.

1. A method for manufacturing a thin film magnetic head comprising arecording pole portion including a first pole portion, a gap filmadjacent to the first pole portion and a second pole portion having afirst magnetic film and a second magnetic film, the first magnetic filmbeing adjacent to the gap film and having a higher saturated magneticflux density than the second magnetic film, the second magnetic filmbeing adjacent to the first magnetic film comprising the steps of:forming a non-magnetic film over the gap film, forming, in thenon-magnetic film, a hollowed hole, exposing the gap film, having apattern corresponding to a primary pattern which is larger than adefinitive pattern of the first magnetic film, forming a magnetic filmto be the first magnetic film in the primary pattern on the remainingnon-magnetic film and the exposed gap film in the bottom of the hollowedhole, forming the first magnetic film having the primary pattern byflattening the first magnetic film so that the surface of the part ofthe first magnetic film formed in the hollowed hole can have asubstantially same level as that of the surface of the remainingnon-magnetic film, forming a plate underfilm on the patterned firstmagnetic film and the remaining non-magnetic film, forming, on the plateunderfilm, frames to be used in a frame-plating method for the secondmagnetic film so as to be separated, on the first magnetic film, in thetrack direction parallel to the surface of the first magnetic film andcover both edges of the first magnetic film and parts of the remainingnon-magnetic film around the edges, sticking a plate film to be thesecond magnetic film on the parts of the plate underfilm not covered bythe frames, removing the frames, removing the parts of the plateunderfilm exposed after removing the frames, forming a mask to cover thefirst and second magnetic films after removing the plate underfilm,removing the parts of the plate film and the plate underfilm not coveredby the mask, and etching the first magnetic film into the definitivepattern through the second magnetic film as a mask.
 2. A method formanufacturing a thin film magnetic head as defined in claim 1, whereinthe thin film magnetic head further comprises a reading magnetoresistiveeffective element.